An image forming apparatus includes the following elements. An image forming unit forms an image by using plural predetermined colors. An index forming unit causes the image forming unit to form three or more consecutive image correcting indexes of one type by using an identical color, the image correcting indexes being used for correcting misregistration of an image to be formed. The image correcting indexes are sequentially transferred to an image carrier. A detector includes a light source emitting light to the image correcting indexes and a light receiver receiving light reflected by the image carrier and the image correcting indexes to generate a detection signal. A position specifying unit specifies a position of an image correcting index located at the center of three consecutive image correcting indexes by using the detection signal. A misregistration correcting unit corrects misregistration of an image to be formed by using the specified position.